Semiconductor device, manufacturing method for semiconductor device and mounting method for the same

ABSTRACT

A semiconductor device in accordance with the present invention reduces cracks occurring in a junction between a semiconductor device and a mounting substrate due to a heat stress when the semiconductor device is mounted on a printed circuit board or the like. The semiconductor device has a semiconductor element having a thickness of 200 μm or less, an electrode pad formed an the semiconductor element, a post electrically connected to the electrode pad, and a sealing resin for sealing a surface where circuitry is formed and the post. Furthermore, a manufacturing method for a semiconductor device in accordance with the present invention includes a step for forming an electrode pad on a main surface of a semiconductor wafer, a step for forming a post to be connected to the electrode pad, a step for resin-sealing the main surface of the semiconductor wafer and the post, a step for forming a groove from a surface of the resin to a predetermined depth of the semiconductor wafer, and a step for polishing a rear surface of the semiconductor wafer to a bottom of the groove and dividing the semiconductor wafer into individual semiconductor devices.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a semiconductor device and amanufacturing method for the same and, more particularly, to a packageof the semiconductor device.

[0003] 2. Description of the Related Art

[0004] In recent years, with the increasing mounting density ofsemiconductor devices, chip-size packages or similar types ofsemiconductor devices are drawing attention.

[0005] Hitherto, as such a type of chip-size packages, one shown in FIG.9 has been available. A semiconductor device shown in FIG. 9 haselectrode pads 2 formed on a semiconductor element 1 having a thicknessof 400 μm, and posts 3 composed of copper or the like electricallyconnected to the electrode pads 2 are formed thereon. The surface of thesemiconductor element and the posts 3 are sealed by a resin 4 that isapproximately 100 μm thick. Bumps 5 composed of solder or the like areformed on the posts 3 exposed on a resin surface.

[0006] Referring to FIG. 10, a manufacturing method for a conventionalsemiconductor device will be described.

[0007] Posts 101 made of copper or the like are formed on a wafer 100,which is a semiconductor substrate as illustrated in FIG. 10-A. In thisstate, a resin 102 is charged to cover the entire wafer as illustratedin FIG. 10-B. The entire surface is polished until the posts 101 areexposed on the surface as illustrated in FIG. 10-C. Then, bumpelectrodes 103 made of solder or the like are formed on the surfaces ofthe posts 101 as illustrated in FIG. 10-D. Lastly, the wafer is cut anddivided into individual semiconductor devices as illustrated in FIG.10-E.

[0008] The conventional structure and manufacturing method have beenposing problems including one in which a crack occurs at a junctionbetween a semiconductor element and a mounting substrate due to thermalstress when mounting a semiconductor device on a printed board or thelike (refer to FIG. 11). In the manufacturing method for theconventional semiconductor devices, if the stress of a sealing resin ishigh, then a wafer develops a warp when resin sealing is performed. Awarped wafer is difficult to be fixed when dividing it into individualsegments as shown in FIG. 12.

SUMMARY OF THE INVENTION

[0009] To solve the problems mentioned above, a semiconductor device inaccordance with the present invention has a semiconductor element havinga thickness of 200 μm or less, an electrode pad formed on thesemiconductor element, a post electrically connected to the electrodepad, and a sealing resin for sealing a surface of the semiconductorelement whereon circuitry is formed and the post.

[0010] Furthermore, a manufacturing method for a semiconductor device inaccordance with the present invention includes a step for forming anelectrode pad on a main surface of a semiconductor wafer, a step forforming a post to be electrically connected to the electrode pad, a stepfor resin-sealing the main surface of the semiconductor wafer and thepost, a step for forming a groove from a resin surface to apredetermined depth of the semiconductor wafer, and a step for polishinga rear surface of the semiconductor wafer to a bottom of the groove anddividing the semiconductor wafer into individual semiconductor devices.

[0011] A mounting method for a semiconductor device in accordance withthe present invention includes a step for preparing a semiconductordevice in which a main surface of a semiconductor element having athickness of 200 μm or less has been resin-sealed, a step for disposingthe semiconductor device on a mounting substrate, and a step forconnecting the semiconductor device and the mounting substrate by heattreatment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a diagram showing a structure of a semiconductor deviceof a first embodiment in accordance with the present invention.

[0013]FIG. 2 is a diagram showing a temperature cycle characteristic ofa semiconductor device in accordance with the present invention.

[0014]FIG. 3 and FIG. 4 are process diagrams showing steps of amanufacturing method for the semiconductor device of the firstembodiment in accordance with the present invention.

[0015]FIG. 5 is a diagram showing a structure of a semiconductor deviceof a second embodiment in accordance with the present invention.

[0016]FIG. 6 and FIG. 7 are process diagrams showing steps of amanufacturing method for the semiconductor device of the secondembodiment in accordance with the present invention.

[0017]FIG. 8 is an enlarged view of a groove in the manufacturing methodfor the semiconductor device of the second embodiment in accordance withthe present invention.

[0018]FIG. 9 is a diagram showing a structure of a conventionalsemiconductor element.

[0019]FIG. 10 is a process diagram showing steps of a manufacturingmethod for a conventional semiconductor element.

[0020]FIG. 11 and FIG. 12 are diagrams showing problems with aconventional art.

[0021]FIG. 13 and FIG. 14 are process diagrams showing steps of amanufacturing method for a semiconductor device of a third embodiment inaccordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT First Embodiment

[0022]FIG. 1 is a diagram showing a structure of a semiconductor devicein a first embodiment according to the present invention. In conjunctionwith FIG. 1, the first embodiment of the invention will be described.The same components as those in FIG. 8 will be assigned the samereference numerals, and descriptions will be given thereof. In thedrawings, a thickness of a semiconductor element or a resin will beindicated by dashed lines or the like.

[0023] A semiconductor element 1 is formed to be thinner than 400 μm,which is a thickness in a conventional structure. In this embodiment,the semiconductor element 1 is 100 μm thick.

[0024] Aluminum electrode pads 2 are formed at predetermined locationson a main surface of the semiconductor element 1. Posts 3 composed ofcopper are formed on the semiconductor element, the height of the posts3 being 50 μm. The posts 3 are electrically connected to the aluminumelectrode pads 2.

[0025] The main surface (a surface where a circuit is formed) of thesemiconductor element 1 and the posts 3 are sealed by a resin 4, thethickness of the resin 4 being 50 μm, which is identical to thethickness of the posts 3. Bump electrodes 5 are formed on the resin 4.In this embodiment, the bump electrodes 5 composed of solder or the likeare formed on the posts 3 exposed on the surface of the resin 4.

[0026]FIG. 2-A is a diagram showing results of a temperature cycle testconducted with a semiconductor device mounted on a mounting substratesuch as a printed circuit board. In FIG. 2-A, the axis of abscissaindicates the thickness of a semiconductor element, while the axis ofordinates indicates the number of cycles at which a crack occurs in ajunction (a solder ball in this embodiment) between the semiconductordevice and the mounting substrate in relation to a distortion observedbetween the mounting substrate and the semiconductor device.

[0027] Due to a difference in thermal expansion coefficient, adistortion takes place between the semiconductor device and the mountingsubstrate. Decreasing the thickness of the semiconductor element 1 addsto the flexibility of the semiconductor element itself; hence, thesemiconductor element itself will absorb the distortion during heating.FIG. 2-A shows that the maximum distortion of a junction decreases asthe thickness of the semiconductor element is decreased.

[0028] Furthermore, as the semiconductor element is made thinner, thenumber of temperature cycles at which a crack appears in the solder ballincreases.

[0029] The effect is remarkably noticeable when the thickness of thesemiconductor element is reduced to 200 μm or less.

[0030]FIG. 2-B shows temperature characteristics observed when thethickness of the resin sealing the main surface of the semiconductorelement is changed, with the thickness of the semiconductor elementbeing left unchanged. Data shown in FIG. 2-B has been obtained when thethickness of the semiconductor element was set to 200 μm, and thethickness of the resin was changed to about 50 μm, about 60 μm, about100 μm, and about 150 μm, respectively.

[0031] As compared with a case wherein the ratio of the thickness of thesemiconductor element to the thickness of the resin is set to 4 to 1,the maximum distortion is reduced when the ratio of the thickness of thesemiconductor element to the thickness of the resin is set to 2 to 1, or1 to 1 as in the case of the present invention. This indicates that theflexibility of the semiconductor element itself increases with resultantbetter temperature characteristics when the thickness of the resin isgreater than the thickness of the semiconductor element. Marked effectcan be observed when the thickness of the resin is set to a half or moreof the thickness of the semiconductor element.

[0032] More detailed experiments and simulations carried out by theinventors have revealed that, in the semiconductor device in accordancewith the present invention, cracks that occur primarily when mountingthe semiconductor device on a substrate can be sufficiently restrainedby setting the thickness of the semiconductor element to 200 μm or lessand by setting the thickness of the resin to a half or more of thethickness of the semiconductor element.

[0033]FIG. 3 and FIG. 4 illustrate a manufacturing method for asemiconductor device of the first embodiment in accordance with theinvention.

[0034] Referring to FIG. 3 and FIG. 4, the manufacturing method for asemiconductor device of the first embodiment in accordance with theinvention will be described.

[0035] Copper posts 31 having a height of approximately 50 μm are formedon a main surface (where a circuit is formed) of a semiconductor wafer30 by electroplating or the like as shown in FIG. 3-A. The posts 31 areelectrically connected to electrode pads (not shown) formed on the wafer30.

[0036] A resin 32 is charged according to a transfer molding method, apotting method, a printing method, etc. to cover the main surface of thesemiconductor wafer 30 and the posts 31 (see FIG. 3-B).

[0037] The semiconductor wafer 30 at this stage has a sufficientthickness to prevent a warp from taking place due to stress of the resin32, etc.

[0038] The surface of the resin 32 is polished by a polishing blade 33until the posts 31 buried in the resin 32 are exposed and the heights ofthe resin 32 and the posts 31 reach 50 μm (see FIG. 3-C).

[0039] Grooves 35 are formed in the surface covered with the resin 32 byan outer peripheral blade 34 that rotates at a high speed, the grooves35 being formed at locations where the wafer is divided into individualsemiconductor devices later. The depth of the grooves 35 is determinedon the basis of a thickness of the semiconductor elements in the finalindividual semiconductor devices. In this embodiment, the thickness ofthe semiconductor element 1 is set to 100 μm, so that the grooves havinga depth of 120 μm are formed in the semiconductor wafer 30. The depthfrom the resin surface to the bottoms of the grooves 35 formed in thisprocess step will be a sum of the resin thickness and the depth of thegrooves in the wafer, namely, 50+120=170 μm (see FIG. 3-D).

[0040] Then, a grinding tape 36 is attached to the surface of thesubstrate whereon the resin has been deposited. The grinding tape can beeasily peeled off by radiating ultraviolet rays thereby to weaken itsadhesive strength.

[0041] The surface to which the grinding tape 36 has been attached isfixed onto a grinding stage (not shown) as shown in FIG. 4-A. Then, theentire rear surface of the wafer 30 is polished with the wafer 30secured to the grinding stage until the bottoms of the grooves 35, whichhave been formed in the preceding step, are reached.

[0042] Polishing the rear surface of the wafer 30 until the bottoms arereached causes the wafer 30 to be divided into individual semiconductordevices. Thus, the separated semiconductor devices 37 from the wafer arearranged on the grinding tape 36 as shown in FIG. 4-B.

[0043] A mounting tape 38 is attached to the rear surface, which hasbeen polished, before the semiconductor devices 37 are moved to thefollowing step wherein bump electrodes or the like are formed asnecessary.

[0044] In the manufacturing method in this embodiment, the wafer isfirst sealed with the sufficiently thick resin, so that there should beno danger of a warp occurring in wafer at this stage. Thereafter, thegrooves are formed in the wafer from the resin side, then the entirerear surface of the wafer is polished to the bottoms of the groovesthereby to divide the wafer into separate semiconductor devices.

[0045] The method described above makes it possible to solve the warpproblem with a wafer when fixing the wafer.

[0046] Even when the semiconductor element finally becomes thin, theindividual semiconductor devices are sufficiently smaller than thewafer, thus solving the stress problem attributable to a resin. Themanufacturing method in accordance with the present invention also makesit possible to provide a semiconductor device having a thinnersemiconductor element than a conventional semiconductor element.

Second Embodiment

[0047]FIG. 5 shows a structure of a semiconductor device in a secondembodiment in accordance with the present invention.

[0048] Referring to FIG. 5, the second embodiment will now be described.In the description, like components as those in FIG. 1 will be assignedlike reference numerals.

[0049] A semiconductor element 1 is formed to be thinner than aconventional structure that measures 400 μm. A central portion 11 of thesemiconductor element 1 in this embodiment is 100 μm thick. Thethickness of the semiconductor device 1 is smaller in a peripheralportion 12 thereof than in the central portion 11 thereof, meaning thatthe peripheral portion of the semiconductor element 1 has a steppedportion 6. The stepped portion 6 is formed on a main surface side (thesurface where circuitry is formed) of the semiconductor element. A depthof the stepped portion 6, i.e. a distance from the surface of thecentral portion to the top of the peripheral portion 12, isapproximately 30 μm.

[0050] Aluminum electrode pads 2 are formed at predetermined locationson the main surface portion of the semiconductor element 1, and copperposts 3 are also formed on the semiconductor element 1, the height ofthe posts 3 being 50 μm. The posts 3 are electrically connected to thealuminum electrode pads 2.

[0051] The main surface of the semiconductor element 1 and the posts 3are sealed by a resin 4 which has a thickness of 50 μm which isidentical to the height of the posts 3. Bump electrodes 5 are formed onthe resin 4. In this embodiment, the bump electrodes 5 composed ofsolder or the like are formed on the posts 3 exposed on the surface ofthe resin 4.

[0052] In the semiconductor device according to the present invention,the peripheral portion 12 of the semiconductor element 1 is thinner thanthe central portion 11, forming the stepped portion 6. The steppedportion 6 is formed on each of four sides to surround the centralportion 11 of the semiconductor element. This arrangement preventscracks or the like during mounting as in the case of the firstembodiment.

[0053] The presence of the stepped portion adds to a portion of contactbetween the resin 4 and the semiconductor element 1 at the peripheralportion 12 of the semiconductor element 1, thus minimizing the chancesof peeling off of the resin. Moreover, even if water enters through aninterface between the semiconductor element 1 and the resin, the waterwill not reach the central portion where circuitry is formed.

[0054]FIG. 6 and FIG. 7 illustrate a manufacturing method for asemiconductor device according to the second embodiment of theinvention.

[0055] Referring to FIG. 6 and FIG. 7, the manufacturing method for thesemiconductor device according to the second embodiment of the inventionwill be described. In the description, like components as those in FIG.3 and FIG. 4 will be assigned like reference numerals.

[0056] Copper posts 31 having a height of approximately 50 μm are formedon the main surface of a semiconductor wafer 30 by electroplating or thelike (see FIG. 6-A). The posts 31 are electrically connected toelectrode pads (not shown) formed on the wafer 30.

[0057] First grooves 61 are formed in the main surface of thesemiconductor wafer 30 by an outer peripheral blade 60 that are rotatedat a high speed. The first grooves 61 are formed in portions thatprovide the peripheral portions of individual semiconductor elements.The thickness of the blade 60 used for forming the first grooves isapproximately 50 μm. The grooves 61 are formed to have a width that is 1to 5 μm larger than the blade thickness. The depth of the first grooves61 is 30 μm (see FIG. 6-B).

[0058] The main surface, where circuitry is formed, of the semiconductorwafer 30 is filled with a resin 32 by a transfer molding method, apotting method, a printing method, etc. (see FIG. 6-C).

[0059] The semiconductor wafer 30 in this step is sufficiently thick, sothat it does not develop a warp caused primarily by stress of the resin32.

[0060] The surface of the resin 32 is polished by a polishing blade 33until the posts 31, which have been buried in the resin, are exposed,and the heights of the resin 32 and the posts 31 reach 50 μm (see FIG.6-D).

[0061] Second grooves 63 are formed using an outer peripheral blade 62,which rotates at a high speed, in the surface covered with the resin 32as illustrated in FIG. 7-A. The second grooves 63 having a width smallerthan that of the first grooves 61 are formed in the first grooves 61, anenlarged view thereof being given in FIG. 8. The thickness of the blade62 for forming the second grooves 63 is approximately 30 μm.

[0062] The depth of the second grooves 63 is determined on the basis ofa thickness of the semiconductor elements in the final individualsemiconductor devices. In this embodiment, the thickness of centralportions of the semiconductor elements is set to 100 μm, so that thegrooves having a depth of 120 μm measured from the main surface of thesemiconductor wafer 30 are formed in the semiconductor wafer 30. Thedepth from the resin surface to the bottoms of the second grooves 63 isa sum of the resin thickness, the depth of the first grooves, and thedepth of the grooves in the wafer, namely, 50+30+90=170 μm.

[0063] Then, a grinding tape 36 is attached to the surface whereon theresin has been deposited. The grinding tape 36 can be easily peeled offby radiating ultraviolet rays thereby to weaken its adhesive strength.

[0064] The grinding tape 36 is fixed onto a grinding stage (not shown)as shown in FIG. 7-B. Then, the rear surface of the wafer 30 is polishedwith the wafer 30 secured to the grinding stage until the bottoms of thesecond grooves 63, which have been formed in the preceding step, arereached (see FIG. 7-C).

[0065] Polishing the rear surface of the wafer until the bottoms of thesecond grooves 63 are reached causes the wafer 30 to be divided intoindividual semiconductor devices. In other words, separatedsemiconductor devices 37 are arranged on the grinding tape 36.

[0066] Thereafter, a mounting tape 38 is attached to the polished rearsurface of the wafer before the semiconductor devices 37 are supplied tothe following step.

[0067] In this embodiment, the depth of the first grooves is set to 30μm. Forming the first grooves 61 to be excessively deep would add toinfluences of resin stress. Experiments performed by the inventors haverevealed that, if the depth of the first grooves is set to exceed 30 μm,then a wafer incurs influences exerted by the resin stress, resulting ina likelihood of a warp when the wafer is fixed. Preferably, the firstgrooves 61 are formed so that they are deeper than the portion of thewafer surface whe circuitry is formed, namely, in a range of about 10 μmto about 30 μm.

[0068] The method described above makes it possible to solve the warpproblem with a wafer when fixing the wafer.

[0069] According to the manufacturing method in this embodiment, a waferis unlikely to incur a warp or the like when it is fixed, as in the caseof the manufacturing method for a semiconductor device according to thefirst embodiment.

[0070] Moreover, forming the first grooves makes it possible to providea semiconductor device that minimizes chances for a resin to peel offand that is capable of preventing the entry of water.

Third Embodiment

[0071]FIG. 13 and FIG. 14 illustrate another manufacturing method for asemiconductor device in accordance with the present invention. Thefollowing will describe the manufacturing method according to theinvention, taking the first embodiment as an example. In thedescription, like components as those in FIG. 3 and FIG. 4 will beassigned like reference numerals.

[0072] The process up to the step wherein the resin 32 on thesemiconductor wafer 30 is polished by the polishing blade 33 is the sameas that of the first embodiment (FIG. 13-A through FIG. 13-C).

[0073] Thereafter, grooves 35 are formed using an outer peripheral blade34, which rotates at a high speed, in a surface covered with a resin 32.The grooves 35 are formed at locations where the wafer is divided intoindividual semiconductor devices.

[0074] The third embodiment differs from the first embodiment in thedepth of the grooves. In this embodiment, the thickness of asemiconductor element 1 is set to 100 μm, so that the grooves having adepth of 50 μm are formed in the semiconductor wafer 30. Hence, thedepth from a resin surface to bottoms of the grooves 35 formed in thestep is a sum of the thickness of the resin and the depth of grooves inthe wafer, namely, 50+50=100 μm (see FIG. 13-D).

[0075] After that, a grinding tape 36 is attached to the surface of asubstrate whereon the resin has been deposited. The grinding tape can beeasily peeled off by radiating ultraviolet rays thereby to weaken itsadhesive strength. The surface to which the grinding tape 36 has beenattached is fixed onto a grinding stage (not shown) as shown in FIG.14-A. Then, the entire rear surface of the wafer 30 is polished with thewafer 30 secured to the grinding stage until a level which is 50 μmabove the bottoms of the grooves 35 is reached. In other words, thepolishing is finished when the thickness of the semiconductor wafer 30reaches 100 μm. At this stage, portions where the grooves 35 have beenformed develop cracks that reach the rear surface of the semiconductorwafer 30 primarily due to stress during the polishing (see FIG. 14-B).Thus, the semiconductor devices are divided into individual pieces.

[0076] To securely divide the wafer into the semiconductor devices, itis recommended to subject the rear surface of the wafer to processing bya roller 140 or the like. As the roller 140 rolls, portions of the waferwhere the grooves 35 have been formed are broken, allowing the wafer tobe securely divided into individual semiconductor devices. The stepsthereafter are identical to those of the manufacturing method accordingto the first embodiment.

[0077] The same manufacturing method as that of the third embodiment canbe implemented in the manufacturing method according to the secondembodiment by setting the depth of the second grooves to 100 μm.

[0078] According to the manufacturing method in the third embodiment,grooves formed from the main surface side of a semiconductor wafer canbe made shorter, thus permitting reduced stress applied to individualsemiconductor devices.

[0079] The semiconductor devices of the first and second embodiments inaccordance with the present invention are disposed on a mountingsubstrate such as a printed circuit board, and after that, they areconnected onto a mounting substrate by heat treatment such as reflow ofsolder. Using the semiconductor device in accordance with the presentinvention permits a mounting method that reduces cracks in a junctionbetween a mounting substrate and a semiconductor device.

[0080] As described in detail above, a semiconductor device inaccordance with the present invention makes it possible to reduce cracksin a junction between a mounting substrate and a semiconductor device.

[0081] A manufacturing method in accordance with the present inventionmakes it possible to solve problems such as a warp of a wafer when thewafer is fixed.

What is claimed is:
 1. A semiconductor device comprising: asemiconductor element having a thickness of 200 μm or less; an electrodepad formed on said semiconductor element; a post electrically connectedto said electrode pad; and a sealing resin for sealing a surface of saidsemiconductor element whereon circuitry is formed and said post.
 2. Asemiconductor device according to claim 1, wherein a thickness of saidsealing resin is greater than a half of a thickness of saidsemiconductor element.
 3. A semiconductor device according to claim 1,wherein said semiconductor element has a central portion that has afirst thickness and a peripheral portion that has a second thicknessthat is smaller than the first thickness.
 4. A semiconductor deviceaccording to claim 3, wherein a thickness of said sealing resin isgreater than a half of the thickness of the central portion of saidsemiconductor element.
 5. A manufacturing method for a semiconductordevice comprising: a step for forming an electrode pad on a main surfaceof a semiconductor wafer; a step for forming a post to be connected tosaid electrode pad; a step for resin-sealing the main surface of saidsemiconductor wafer and said post; a step for forming a groove from asurface of said resin to a predetermined depth of said semiconductorwafer; and a step for polishing a rear surface of said semiconductorwafer to a bottom of said groove and dividing said semiconductor waferinto individual semiconductor devices.
 6. A manufacturing method for asemiconductor device comprising: a step for forming an electrode pad ona main surface of a semiconductor wafer; a step for forming a post to beconnected to said electrode pad; a step for forming a first groovehaving a first width on the main surface of said semiconductor wafer; astep for resin-sealing the main surface of said semiconductor wafer andsaid post; a step for forming a second groove having a width that issmaller than said first width from a resin surface on said first grooveuntil a predetermined depth of said semiconductor wafer is reached onthe main surface of said semiconductor wafer; and a step for polishing arear surface of said semiconductor wafer to a bottom of said secondgroove and dividing said semiconductor wafer into individualsemiconductor devices.
 7. A mounting method for a semiconductor devicecomprising: a step for preparing a semiconductor device in which a mainsurface of a semiconductor element having a thickness of 200 μm or lesshas been resin-sealed; a step for disposing said semiconductor device ona mounting substrate; and a step for connecting said semiconductordevice and said mounting substrate by heat treatment.
 8. A manufacturingmethod for a semiconductor device, comprising: a step for forming anelectrode pad on a main surface of a semiconductor wafer; a step forforming a post to be connected to said electrode pad; a step forresin-sealing the main surface of said semiconductor wafer and saidpost; a step for forming a groove from a surface of said resin to apredetermined depth of said semiconductor wafer; a step for polishing arear surface of said semiconductor wafer until said semiconductor waferreaches a predetermined thickness; and a step for breaking a portionwhere the groove has been formed in said semiconductor wafer to dividesaid semiconductor wafer into individual semiconductor devices.
 9. Amanufacturing method for a semiconductor device, comprising: a step forforming an electrode pad on a main surface of a semiconductor wafer; astep for forming a post to be connected to said electrode pad; a stepfor forming a first groove having a first width on the main surface ofsaid semiconductor wafer; a step for resin-sealing the main surface ofsaid semiconductor wafer and said post; a step for forming a secondgroove having a width that is smaller than said first width from a resinsurface on said first groove until a predetermined depth of saidsemiconductor wafer is reached on the main surface of said semiconductorwafer; a step for polishing a rear surface of said semiconductor waferuntil said semiconductor wafer reaches a predetermined thickness; and astep for breaking a portion where said second groove has been formed insaid semiconductor wafer to divide said semiconductor wafer intoindividual semiconductor devices.